Implants have been used for reconstructing damaged tissues and restoring their functions. For example, an expandable metal stent is commonly used in transluminal procedures, such as angioplasty, to restore adequate blood flow. However, a stent may stimulate host responses, resulting in thrombosis and restenosis. To avoid these complications, it is often coated with an anti-arteriosclerosis or anti-restenosis agent before being deployed in a blood vessel.
An expandable metal stent has dimensionally manipulatable interstices on its wall. Conventional methods for coating such a stent often lead to bridges, i.e., films spanning interstices. Bridges interfere with the expansion of the stent during its deployment. Also, they may rupture upon expansion and thereby activate platelet deposition due to flow disturbances in a hemodynamic environment. Further, pieces of bridges may fall off and cause downstream emboli. Finally, bridges may prevent endothelial cells from migrating into the stent and encapsulating it.
There is a need for a method of preparing bridge-free coating on a stent, as well as other implants having interstices.